<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    img {
        width: 300px;
        animation-name: suofang;
        animation-duration: 1s;
        animation-timing-function: linear;
        animation-delay: 0.1s;
        animation-iteration-count: infinite;
    }
    
    @keyframes suofang {
        0% {
            transform: scale(1);
        }
        50% {
            transform: scale(0.5);
        }
        100% {
            transform: scale(1);
        }
    }
</style>

<body>
    <img src="https://img0.baidu.com/it/u=3101694723,748884042&fm=26&fmt=auto&gp=0.jpg" alt="">
</body>

</html>